Meeting Abstract
Studies on the biotic impacts of climate warming have overwhelmingly focused on the potential impacts of shifts in mean temperatures. Though changes in mean temperatures correlate with shifts in, for example, phenology and geographic ranges, other “cryptic” changes in temperature may be equally important. Yet, these cryptic changes have received relatively little attention, in part because the organism-appropriate temperature metric is often elusive. As an alternative to defining arbitrary temperature metrics, we evaluated the biotic impacts of cryptic temperature changes by viewing organisms as physiological filters. Thus, we filtered global hourly temperature data through three classes of cryptic temperature effects: 1) non-linear thermal responses using thermal performance curves of insect fitness, 2) hysteresis of thermal effects using degree-day models for corn development, and 3) threshold temperature effects using critical thermal maxima and minima for diverse ectotherms. We then contrasted biotic impacts based on mean temperatures with estimates using hourly temperature data. We found that, using this physiological filter approach, mean temperatures can mask hidden, or “cryptic”, changes in temperature and greatly alter predictions of the biotic impacts of climate change.
